单项选择题
设z=xcosy-2yex+2x,则、分别为()。
A.cosy+2yex+2xln2,xsiny-ex B.cosy-2yex-2xln2,xsiny+2ex C.cosy-2yex+2xln2,-xsiny-2ex D.siny-2yex+2xln2,cosy-2ex
A.A B.B C.C D.D